scholarly journals Simultaneous Preparation of Facial and Meridional Isomer of Cobalt-Amino Acid Complexes and their Characterization

2009 ◽  
Vol 2 (1) ◽  
pp. 91-98 ◽  
Author(s):  
M. M. Alam ◽  
S. M. S. Islam ◽  
S. M. M. Rahman ◽  
M. M. Rahman
Keyword(s):  
Amino Acid ◽  
Ir Spectroscopy ◽  
Chemical Analysis ◽  
Sufficient Information ◽  
Carboxyl Group ◽  
Direct Impact ◽  
Acid System ◽  
Visible Spectroscopy ◽  
Uv Visible

Preparation and characterization of various complexes of cobalt (III)-amino acid system, especially cobalt (III) glycinato and cobalt (III) alaninato complexes are reported. The identification of the various isomers of these complexes is also reported. The various isomers are separated from their mixture by fractional crystallization. Each of these complexes has been characterized by observing physical characteristics, chemical analysis, UV-visible spectroscopy and IR-spectroscopy. The direct impact of geometry of the complexes to IR stretching frequencies and UV-visible spectral data of amino and carboxyl group in the complexes provided sufficient information about the geometry. A prediction about the geometries of the synthesized has also been focused.   Keywords: Cobalt; Amino acid; Isomers; UV-visible; IR. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.  DOI: 10.3329/jsr.v2i1.2032                 J. Sci. Res. 2 (1), 91-98 (2010)    

scholarly journals Preliminary Characterization of Melanin Isolated from Fruits and Seeds of Nyctanthes arbor-tristis

2009 ◽  
Vol 1 (3) ◽  
pp. 655-661 ◽  
Author(s):  
P. Kannan ◽  
D. Ganjewala
Keyword(s):  
Ir Spectroscopy ◽  
Metal Ions ◽  
Ir Spectrum ◽  
Alkaline Extraction ◽  
Visible Spectroscopy ◽  
Tissue Weight ◽  
Different Temperatures ◽  
Uv Visible ◽  
The Stability

Melanin from Nyctanthes arbor-tristis fruits and seeds was isolated and purified by alkaline extraction, acid hydrolysis and organic solvents. Each, fruit and seed yielded melanin 50 mg/100g tissue weight. The melanins of fruit and seeds were analyzed by UV-visible and infrared (IR) spectroscopy for characterization. The IR spectrum of fruit and seed melanins did not match with each other and the seed melanin could be distinguished by their sharp peat at 285 nm from the fruit melanin in IR spectrum. Two melanins have shown absorptions above and below 1600 cm-1 in their respective IR spectrum. The melanins thus characterized were tested for their stability after incubating at different temperatures and in presence of oxidants (KMnO4 and K2Cr2O7) and metal ions (Mg++ and Zn++) for a specified period. The stability of the melanin was assessed by measuring changes in the absorbance at 285 nm. The results revealed that the fruit melanin was more stable at 50 ºC while the seed melanin was quite stable at 25 ºC. However, their stability was markedly affected by oxidants and metal ions.  Keywords: Melanin; Nyctanthes arbor-tristis; UV-visible spectroscopy; IR-spectroscopy; Oxidant. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i3.2005               J. Sci. Res. 1 (3), 655-661 (2009)  

scholarly journals Degradasi Tirosina Menggunakan Mangkinfoto Berasaskan TiO2

2012 ◽  
Author(s):  
Rusmidah Ali ◽  
Siti Salamah Maisoan @ Selamat
Keyword(s):  
Amino Acid ◽  
Metal Ions ◽  
Uv Light ◽  
Degradation Process ◽  
Aqueous System ◽  
Visible Spectroscopy ◽  
Photo Degradation ◽  
Efficient System ◽  
Catalyst Powder ◽  
Uv Visible

Asid amino merupakan bahan asas dalam tisu tumbuhan dan haiwan. Tirosina (Tr) salah satu jenis asid amino yang mengandungi gelang aromatik, telah dipilih sebagai sampel untuk proses degradasi dalam medium akueus. Ini bertujuan melihat kesan penggunaan mangkinfoto dalam sinaran ultralembayung (λ < 400 nm) atau cahaya matahari ke atas molekul tirosina. Kajian telah dijalankan menggunakan sistem cahaya, mangkin serbuk TiO2, hidrogen peroksida, H2O2 dan ion logam. Penambahan ion logam seperti Ni2+, Cu2+, Ag+, Mn2+, Co2+, Fe2+ dan Cd2+ dan agen pengoksidaan, iaitu hidrogen peroksida adalah untuk mendapatkan kaedah yang paling cekap. Keputusan menunjukkan penambahan H2O2 dan ion Fe2+ dan Ni2+ berjaya meningkatkan kecekapan proses degradasifoto tirosina. Ion Ni2+ memberikan keputusan terbaik berbanding ion-ion lain. Ion Cu2+, Ag+, Mn2+ dan Cd2+ merencat proses degradasi. Keputusan juga menunjukkan cahaya matahari adalah setanding dengan cahaya ultralembayung. Kepekatan H2O2 terbaik adalah 5.0 x 10-2M dan semakin banyak TiO2 digunakan semakin baik peratus degradasi tirosina. Oleh itu kaedah optimum untuk proses degradasifoto ialah Tr 2.5 x 10-4 M + TiO2 + H2O25.0 x 10-3 M + Mn+ 1.0 x 10-2 M. Proses degradasifoto dikaji menggunakan spektroskopi ultralembayung-nampak pada julat panjang gelombang 400-200 nm. Kata kunci: Tirosina; degradasifoto; serbuk TiO; akueus Amino acid is a basic component in plant or animal tissue. Tyrosine (Tr), an amino acid which contains aromatic ring, was chosen as a sample for a photodegradation process in an aqueous system. The purpose of the experiment is to study the effect of photocatalysis under UV (λ < 400 nm) or sunlight on tyrosine. The experiment was carried out by using UV light, catalyst powder (TiO2), hidrogen peroxide H2O2 and metal ions system. The addition of oxidising agent H2O2 and metal ions such as Ni2+, Cu2+, Ag+, Mn2+, Co2+, Fe2+ and Cd2+ were used in order to achieve the most efficient system. Results showed that the system with added H2O2 and metal ions such as Ni2+ and Fe2+ had successfully enhanced the process of the tyrosine photodegradation. Other metal ions system such as Cu2+, Ag+, Mn2+ and Cd2+ were found to inhibit the degradation process. The results also showed that sunlight was comparable to ultraviolet light. The best H2O2 concentration was 5.0 x 10-2 M and the percentage of tyrosine degradation increased with the addition of more TiO2) by mass. Therefore, the optimum condition for tyrosine photodegradation process was in Tr 2.5 x 10-4 M + TiO2 + H2O2 5.0 x 10-3 M + H2O2 1.0 x 10-2 M. The dissappearance of tyrosine in the photo degradation process was monitored by UV-visible spectroscopy between 400-200 nm. Key words: Tyrosine; photodegradation; TiO2 powder; akueus

Synthesis and Characterization of Gold Nanoparticles Synthesized in Gel and Paper by Electrolysis

2019 ◽  
Vol 824 ◽  
pp. 163-167
Author(s):  
Pema Dechen ◽  
Ekasith Somsook
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Gold Nanoparticles ◽  
Room Temperature ◽  
Synthesis And Characterization ◽  
Visible Spectroscopy ◽  
Gold Leaf ◽  
Uv Visible ◽  
Scanning Electron

In this report, synthesis and characterization of gold nanoparticles (AuNPs) from gold leaf by electrolysis in two different media (gel and paper) in presence of sodium chloride (NaCl), glucose (C6H12O6) and polyvinyl pyrrolidone (PVP) at room temperature were investigated. Graphite was used as two electrodes, NaCl was used as an electrolyte, C6H12O6 was used as reducing agent and PVP was used as stabilizer to control the aggregation of the nanoparticles. UV-Visible spectroscopy (UV-Vis) and scanning electron microscopy (SEM) were used to confirm the characteristics and morphologies of the synthesized AuNPs.

In Situ Polymerization and Characterization of Poly(ε-caprolactone)/Layered Double Hydroxide Nanocomposites

2012 ◽  
Vol 557-559 ◽  
pp. 371-374
Author(s):  
Lian Liu ◽  
Teng Yu ◽  
Pei Wang ◽  
Guang Shuo Wang
Keyword(s):  
Layered Double Hydroxide ◽  
In Situ Polymerization ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Uv Visible ◽  
Absorbance Peak ◽  
Double Hydroxide

Nanocomposites of poly(ε-caprolactone) (PCL) and layered double hydroxide (LDH) were prepared by in situ polymerization at low LDHs loadings in this work. The resultants were characterized by FTIR spectroscopy, X-ray diffraction (XRD), differential scanning calorimeter (DSC) and UV-visible spectroscopy (UV-vis). FTIR showed that the PCL/LDHs nanocomposites were prepared successfully by in situ polymerization and XRD spectra showed that the crystal structure did not change greatly in the presence of LDHS. DSC results confirmed that LDHs could act as nucleating agents. UV-vis spectra showed that LDHs had stronger absorbance peak than LDH. Moreover, the PCL/LDHs nanocomposites had strong anti-ultraviolet effect by introduction of LDHs into polymer matrix.

Synthesis and NMR Spectroscopic Characterization of Some Fluoro-2H-1-Benzopyran Derivatives

2005 ◽  
Vol 58 (7) ◽  
pp. 517 ◽  
Author(s):  
Yannick Teral ◽  
Gabriel Roubaud ◽  
Claude Aubert ◽  
Robert Faure ◽  
Mylène Campredon
Keyword(s):  
Mass Spectra ◽  
Spectroscopic Characterization ◽  
Molecular Probe ◽  
Visible Spectroscopy ◽  
Chemical Shift Correlation ◽  
Photochemical Process ◽  
Fragment Ions ◽  
Complete Assignment ◽  
Uv Visible

The synthesis of some new fluoro-2H-1-benzopyran derivatives utilizing a reaction between titanium phenolates and β-phenylcinnamaldehydes in toluene is reported. These compounds were characterized by NMR and UV/visible spectroscopy as well as mass spectrometry. In solution all the compounds are photochromic. Complete assignment of the 1H and 13C resonances was achieved by concerted application of homonuclear (gs-COSY), proton-detected (C, H) one-bond (gs-HMQC), and long-range (gs-HMBC) heteronuclear two-dimensional chemical shift correlation experiments using a 500 MHz NMR spectrometer equipped with a cryoplatform and a 5 mm cryoprobe. The mass spectra of the different compounds were characterized by intense molecular and high fragment ions. The introduction of an atom of fluorine as a molecular probe is of interest in determining the mechanistic aspects of the photochemical process.

scholarly journals Synthesis and characterization of Fe(III) complex with thiosemicarbazide-based ligand

2020 ◽  
Keyword(s):  
Mass Spectrometry ◽  
Condensation Reaction ◽  
Azomethine Nitrogen ◽  
Synthesis And Characterization ◽  
Stoichiometric Ratio ◽  
Significant Activity ◽  
Visible Spectroscopy ◽  
Thiol Form ◽  
Uv Visible

Complex iron(III) salicylaldehyde thiosemicarbazone with a formula Na[Fe(STSC)2] have been synthesized. Ligand, salicylaldehyde thiosemicarbazone (SCT) was prepared through the condensation reaction of salycilaldehide with thiosemicarbazide. Na[Fe(STSC)2] has been synthesized by reacting FeCl3 with thiosemicarbazide based ligand bearing ONS donor atoms. Complex has been formulated and characterized by mass spectrometry, infrared and UV/visible spectroscopy. The facts showed the formation of a complex in metal:ligand stoichiometric ratio 1:2. The ligand is coordinated as an ONS tridentate dianion via oxygen atom after the deprotonation of the phenolic OH-group, azomethine nitrogen and sulphur in thiol form of the deprotonated thiosemicarbazide residue. Antioxidant activity was determined, where ligand showed significant activity, while complex, at low concentration, exhibited almost no activity.

Sign in / Sign up

Export Citation Format

Share Document